Color legend incorrect if empty title given from the python

This issue was created automatically from an original Mantis Issue. Further discussion may take place here.

Execute attached script test_color_legend.py (attached in the script+data.tar.gz) several times in the Python Shell.(Before executing correct the path to the deplacements_et_contraintes.0001.vtu file if need). As shown on attached screen-shots, we randomly get a blue color legend at the bottom of the viewer, or a color legend without the Component, or a color legend whose Component is displayed under the color legend.

In the attached script replace
color_legend_title = ""
by the
color_legend_title = " "
and execute the script several times. The display is correct.

It should be able to create a color legend with the empty title from python, as it is possible from the GUI.